Photonic Device Bragg Grating Feedback Force Control
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Solution Overview
Problem
Existing photonic devices struggle to achieve a suitable counter-reaction force for distributed Bragg gratings with gain structures of significant length, particularly when the first dielectric layer thickness is less than 100 nm, leading to inefficient laser operation.
Innovation Solution
The photonic device incorporates a Bragg grating structuring over a first part of the third waveguide section's thickness, located at a distance from the first dielectric layer, allowing for a significant reduction in feedback force and making it suitable for gain structures greater than 50 μm, even with thin dielectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the first dielectric layer thickness is reduced to less than 100 nm, then device integration density is improved, but the Bragg grating feedback force becomes too strong for long gain structures
Solution Approach 1:
The patent segments the dielectric layer structure by introducing a second dielectric layer with different refractive index between the first dielectric layer and the gain structure. This segmentation allows independent optimization of each layer's properties to control the overall feedback force while maintaining thin total thickness.
Solution Approach 2:
The second dielectric layer acts as an intermediary layer with intermediate refractive index between the high-index first dielectric layer and the gain structure. This intermediary layer modifies the optical field distribution and reduces the feedback force strength, enabling long gain structures to operate properly even with thin overall dielectric layers.
2Length of moving object
If the gain structure length is increased to greater than 50 μm, then laser output power is improved, but the required feedback force becomes too weak for thin dielectric layers
Solution Approach 1:
The dielectric layer system is segmented into multiple layers with different optical properties, allowing the feedback force to be tuned independently of the gain structure length. This enables long gain structures to achieve proper feedback strength.
Solution Approach 2:
The patent changes the optical parameters of the dielectric layer system by introducing a second dielectric layer with specific refractive index, thereby adjusting the feedback force magnitude to match the requirements of long gain structures while maintaining compact device dimensions.
3Ease of manufacture
If the first dielectric layer thickness is reduced, then manufacturing complexity is decreased, but laser operation efficiency deteriorates due to insufficient feedback force control
Solution Approach 1:
The dielectric layer is segmented into multiple manufacturable layers, where each layer can be deposited and controlled independently using standard semiconductor fabrication techniques, maintaining ease of manufacture while achieving precise feedback force control.
Solution Approach 2:
By changing the structural parameters of the dielectric system (introducing a second layer with specific refractive index), the patent achieves reliable laser operation without compromising manufacturability, as the additional layer can be integrated into existing fabrication processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces the Bragg grating's feedback force to a level compatible with long gain structures, enhancing laser performance and reducing sensitivity to edge width inhomogeneities, while maintaining low dielectric layer thickness.
Implementation Method 1
the third waveguide section (213) comprises a patterning arranged only in a first part of its thickness, said patterning forming a Bragg grating (223) distributed under the gain structure (310) to form a feedback structure and a resonant cavity
Implementation Method 2
a gain structure (310) in contact with the first dielectric layer (110) and comprising at least one gain medium (321) capable of emitting light
Implementation Method 3
In order to increase the confinement factor of the optical mode in the quantum wells, these are generally framed by two barrier layers
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
The invention relates to a photonic device (1) comprising: a support (120); an intermediate layer (420); an optical guidance stage (200) including a waveguide (210) and a first to fifth waveguide section (211, 212, 213, 214, 215). The photonic device (1) further comprises a first dielectric layer (110) covering the optical guidance stage (200) and a gain structure (310) in contact with the first dielectric layer (110). The second and fourth waveguide sections (212, 214) and the first and second ends of the gain structure (310) form a first and second optical transition zone between a hybrid laser waveguide and, respectively, the first and fifth waveguide sections (211, 215). A Bragg network structure is arranged on a first part of the thickness (e1) of the third waveguide section (213) which is far from the gain structure (310).